Changes in muscle size, architecture, and neural activation after 20 days of bed rest with and without resistance exercise

  title={Changes in muscle size, architecture, and neural activation after 20 days of bed rest with and without resistance exercise},
  author={Yasuo Kawakami and Hiroshi Akima and Keitaro Kubo and Yoshiho Muraoka and Hiroshi Hasegawa and Motoki Kouzaki and Morihiro Imai and Yoji Suzuki and Atsuaki Gunji and Hiroaki Kanehisa and Tetsuo Fukunaga},
  journal={European Journal of Applied Physiology},
Abstract Nine healthy men carried out head-down bed rest (BR) for 20 days. Five subjects (TR) performed isometric, bilateral leg extension exercise every day, while the other four (NT) did not. Before and after BR, maximal isometric knee extension force was measured. Neural activation was assessed using a supramaximal twitch interpolated over voluntary contraction. From a series cross-sectional magnetic resonance imaging scans of the thigh, physiological cross-sectional areas (PCSA) of the… 

Strength, size and activation of knee extensors followed during 8 weeks of horizontal bed rest and the influence of a countermeasure

Changes in the quadriceps femoris muscle with respect to anatomical cross sectional area (CSA), neural activation level and muscle strength were determined in 18 healthy men subjected to 8 weeks of

Changes in lower extremity muscle function after 56 days of bed rest.

It is indicated that bed rest and countermeasure exercises differentially affect the various functions of skeletal muscle and the time course during recovery needs to be considered more thoroughly in future studies, as IPFF declined not only with bed rest but also within the first day of reambulation.

Strength training counteracts motor performance losses during bed rest.

The results indicate that fluctuations in torque during submaximal contractions of the extensor muscles in the leg increase after bed rest and that strength training counteracted the decline in performance.

Musculoskeletal effects of 5 days of bed rest with and without locomotion replacement training

LRT was adequate to maintain muscle size and to even increase knee extensor MVC, but not muscle power and bone integrity, which likely requires more intense and/or longer exercise regimes.

Low‐volume resistance exercise attenuates the decline in strength and muscle mass associated with immobilization

A minimal volume (140 contractions in 14 days) of resistive exercise is an effective countermeasure against immobilization‐induced atrophy of the quadriceps femoris but is only partially effective for the triceps surae.

Skeletal muscle adaptations to physical inactivity and subsequent retraining in young men

The results indicate that the loss of muscle force with 3-week unloading in humans is mostly explained by muscle atrophy and by a decrease in myosin content and all the neuromuscular changes induced by this model of disuse can be fully restored after a resistance training intervention of equal duration.

Resistance training during unweighting maintains muscle size and function in human calf.

It is concluded that dynamic leg press and plantar flexion resistance training during bed rest maintains muscle size and function (torque and T2), and that this training could be useful for prevention of progressive muscle deconditioning during spaceflight.

Shoulder and arm muscle activity during elastic band exercises performed in a hospital bed

The data presented here can be used by physiotherapists as a guideline for selecting suitable and effective strengthening exercises during in-hospital rehabilitation to counteract bed-rest related muscle atrophy in the upper body.

Influence of vibration resistance training on knee extensor and plantar flexor size, strength, and contractile speed characteristics after 60 days of bed rest.

In conclusion, vibration exposure did not enhance the efficacy of resistance training to preserve thigh and calf neuromuscular function during BR, although sample size issues may have played a role.

Prevention of disuse muscular weakness by restriction of blood flow.

The results indicate that repetitive restriction of blood flow to the lower extremity prevents disuse muscular weakness.